str_a=""
if not str_a:
    print('str_a = "" --为空 False')

str_b=None
if not str_b:
    print('str_b = None --为空 False')

"""
str_a = "" --为空 False
str_b = None --为空 False

"""

str_a="123"
if str_a:
    print('111')
else:
    print("222")